Device for testing or checking the dissolution behaviour of pharmaceutical products, system, method, and use thereof

Abstract

The invention relates to a device for testing or checking the dissolution behaviour of pharmaceutical products, comprising at least one stationary unit (12) and at least one unit (14) which is mounted on or in the at least one stationary unit (12) and can be rotated relative to the stationary unit (12), said units being coupled to each other via a communication connection, wherein the at least one stationary unit (12) and the at least one rotatable unit (14) are connected to each other by means of radio for a contactless communication. The invention also relates to a system, to a method, and to the use thereof.

Description

[0001] Device for testing or checking the dissolution behavior of pharmaceutical products, system, method and

[0002] Use for this

[0003] The invention relates to a device for testing or checking the dissolution behavior of pharmaceutical products, a system therefor and / or the use of the device for testing or checking the dissolution behavior of the pharmaceutical products.

[0004] Such devices and methods are generally known. They generally involve devices and methods for simulating the dissolution behavior of pharmaceutical products in the human body or digestive tract and subsequently obtaining and evaluating information about this. Conventional devices for testing the dissolution behavior of dosage units of pharmaceutical products have a dissolution unit with several dissolution vessels, into each of which a test solution and a dosage unit of a pharmaceutical product to be tested, for example a tablet, are introduced for testing. After a tablet, for example, has been introduced into a dissolution vessel in the test solution intended to simulate the conditions prevailing in the human digestive tract, a stirring element is rotated in the test solution at a predetermined speed for a specific period of time.To maintain an electrical connection between a stationary element and a rotating element, solutions are often required that avoid static wires between the elements. For example, a sensor located on a continuously rotating shaft would eventually destroy a conductive wire connecting the rotating sensor to a stationary element signal processor located outside the rotating shaft. Brush slip rings were also used. Brush slip rings are electromechanical components that enable the transfer of power and / or electrical signals between a rotating component and a stationary component. Slip rings are used in a wide variety of devices, including resolution test instruments, helicopter rotors, periscopes, and radar antennas. A conventional slip ring uses a stationary brush-like graphite orA metal contact that rubs against the outer diameter of a corresponding rotating metal ring. The brush is electrically connected to the stationary component, and the corresponding metal ring is electrically connected to the rotating component. As the metal ring rotates, the stationary brush establishes a conductive contact for the electrical signal to the metal ring. The problem is that slip rings introduce electrical noise into the signal, which interferes with signal transmission. Furthermore, these slip rings require regular maintenance to prevent deterioration of the electrical connection due to dirt and normal wear.

[0005] A significant improvement over such brush slip rings was represented by dissolving units with mercury-filled slip rings coupled to a stationary element and a rotating shaft. An example of such a dissolving unit is shown in US Pat. No. 5,589,649. A mercury-filled slip ring uses a container of liquid mercury instead of a brush to establish electrical contact between a stationary component and a rotating component. Mercury-filled slip rings ensure low frictional resistance and stable communication, which significantly minimizes the electrical noise introduced, as well as the deposits and wear typical of brush slip rings.The use of mercury, both in liquid and gaseous form, is problematic because it is extremely toxic. Therefore, mercury-filled slip rings are unsuitable for many applications, including food production and processing, pharmaceutical equipment, or other applications where contamination from a mercury leak poses a high health risk. Furthermore, since March 15, 2011, the export of devices containing mercury components has been restricted within EU member states.

[0006] In addition, devices and methods with contactless communication between rotating and stationary components are proposed. For example, US 10,164,716 B2 describes a method based on optical data transmission using optical infrared (IR) communicators. The use of optical data transmission can be implemented relatively easily, energy-efficiently, and cost-effectively. However, a particular disadvantage of optical data transmission in practice has proven to be that it can only communicate over short distances. The electromagnetic waves of infrared radiation can also be strongly influenced by smoke, fog, dust, and sunlight, among other things. Likewise, transmitters can strongly interfere with each other during optical data transmission. Both the distance and the presence of obstacles or interference can affect the device performance.Data packets in such devices and methods can be significantly impaired or even rendered impossible.

[0007] The present invention is based on the object of providing a device that can prevent the above disadvantages, thus enabling contactless communication, while being extremely simple to manufacture and operate, energy-efficient, and cost-effective, as well as offering high reliability and low susceptibility to interference during data transmission, even over long distances, and of providing a system comprising the device and its use. This object is achieved in a surprisingly simple manner by the features of claim 1.

[0008] By designing the device according to the invention for testing or checking the dissolution behavior of pharmaceutical products with at least one stationary unit or component and at least one unit arranged on or in the at least one stationary unit or component, rotatable relative to the stationary unit, which are coupled to one another via a communication connection, wherein the at least one stationary unit and the at least one rotatable unit are connected to one another via radio for contactless communication, the disadvantages cited in connection with the prior art can be avoided. Thus, a device for / with contactless communication is made possible. At the same time, a device is provided that is extremely simple, energy-efficient, and cost-effective in its manufacture and operation.Furthermore, the device according to the invention exhibits high reliability and low susceptibility to interference during data transmission, even over long distances. The same advantages of the device according to the invention result for a system formed therefrom, for a corresponding method, and for their use.

[0009] Further particularly advantageous details of the device according to the invention are described in claims 2 to 9.

[0010] The features of claim 2 are of particular importance. According to this, the at least one stationary unit or component and the at least one rotatable unit or component are coupled to one another via Bluetooth Low Energy (BLE) for contactless communication. In an alternative embodiment, the at least one stationary unit or component and the at least one rotatable unit or component can also be coupled to one another via another standard, in particular the Wireless M-Bus, LPWan, LiFi, WiFi, LoRa, ZigBee, or Z-Wave standards, instead of Bluetooth Low Energy (BLE).

[0011] In a further embodiment of the invention, the at least one stationary unit and the at least one rotatable unit according to claim 3 each comprise a communication module or communicator, via which the at least one stationary unit and the at least one rotatable unit are connected to one another for contactless communication.

[0012] In this context, it is within the scope of the invention that the communication module or communicator of the at least one stationary unit and the at least one rotatable unit according to claim 4 each comprises a Bluetooth Low Energy (BLE) transmitter. The stationary unit or component therefore comprises a fixed Bluetooth Low Energy (BLE) communication module or a fixed Bluetooth Low Energy (BLE) communicator, and the rotatable unit or component is equipped with a Bluetooth Low Energy (BLE) communication module or a rotating Bluetooth communicator. Alternatively, another transmitter, in particular a wireless M-Bus, LPWan, LiFi, WiFi, LoRa, ZigBee, or Z-Wave standard transmitter, is also possible.

[0013] Furthermore, the features of claim 5 are advantageous, according to which the communication module of the at least one stationary unit and the at least one rotatable unit each comprises a processor, in particular a microcontroller (MCU), for (further) processing the information.

[0014] The same applies to the features of claim 6. Accordingly, the communication module of the at least one stationary unit and the at least one rotatable unit each comprises a memory, in particular a non-volatile memory, preferably a read-only memory (ROM), a non-volatile memory express (NVMe) or a magnetic memory, for storing the information.

[0015] Furthermore, it is within the scope of the invention that the communication module of the at least one stationary unit and the at least one rotatable unit according to claim 7 are arranged in close proximity to one another or are arranged in central proximity and are connected to one another for contactless communication.

[0016] According to the measures of claim 8, the at least one rotatable unit preferably has a rotatable hollow shaft, in particular with an agitator, and at least one sensor arranged on the hollow shaft for detecting or determining parameters characterizing the dissolution behavior of the pharmaceutical products and / or parameters of the solution or medium, in particular temperatures, densities, pH values, electrical conductivities, from which additional concentrations can also be derived, oxygen saturations (residual oxygen), and / or for detecting or determining further parameters, in particular speeds and / or the battery status of the agitator shaft.

[0017] In this case, the at least one sensor according to claim 9 can be arranged at one end, in particular the free end, of the hollow shaft and can be connected to the communication module of the rotatable unit at the other end of the hollow shaft via an electronic connection through the hollow shaft to the communication module of the rotatable unit.

[0018] Most preferably, a system according to the measures of claim 10 is for forming with a device comprising at least one or more additional stationary units and one or more additional rotatable units.

[0019] This object is further achieved in procedural terms by the features of claim 11. Accordingly, the invention provides a method for operating a device or a system according to the invention, in which the at least one stationary unit and the at least one rotatable unit are connected to one another by radio for contactless communication, wherein analog information detected by the at least one sensor of the at least one rotatable unit is digitized, coupled and transmitted to the stationary unit and subsequently processed by the stationary unit.

[0020] According to claim 12, it is within the scope of the invention that the information transmitted from the at least one rotatable unit coupled to the stationary unit is processed by a processor of the stationary unit.

[0021] Preferably, the at least one stationary unit and the at least one rotatable unit according to claim 13 are continuously coupled to one another.

[0022] Finally, according to claim 14, the at least one stationary unit and the at least one rotatable unit are coupled to one another and to one or more additional rotatable units.

[0023] This object is finally achieved in terms of use by the features of claim 15.

[0024] Accordingly, it is within the scope of the invention to use a device or a system according to the invention for testing or checking the dissolution behavior of pharmaceutical products, in particular for simulating the dissolution behavior of the pharmaceutical products in the human body, very preferably for simulating the dissolution behavior of the pharmaceutical products in the human digestive tract.

[0025] Further features, advantages and details of the invention will become apparent from the following description of a preferred embodiment of the invention and from the drawings.

[0026] Fig. 1 is a schematic, perspective partial view of an embodiment of a dissolution test device according to the invention,

[0027] Fig. 2 is a perspective view of an embodiment of a rotating contactless communicator according to the invention of the embodiment of the resolution test device according to the invention corresponding to Fig. 1,

[0028] Fig. 3 is a partially broken-away, perspective exploded view of the embodiment of the rotary contactless communicator of the embodiment of the resolution test device according to the invention corresponding to Fig. 2, in an enlarged view,

[0029] Fig. 4 is a partially broken away perspective view of the embodiment of the rotary contactless communicator of the embodiment of the resolution test device according to the invention corresponding to Fig. 1,

[0030] Fig. 5 and 6 are a front and a rear view of the inventive embodiment of the rotating contactless communicator corresponding to Fig. 4,

[0031] Fig. 7 is a simplified block diagram with the essential elements of the embodiment of the device 10 according to the invention corresponding to Fig. 1, and

[0032] Fig. 8. a perspective partial view of a system according to the invention with several rotating units of the device according to the invention.

[0033] In the following description of an embodiment of a device 10 designed according to the invention, corresponding, identical components are each provided with identical reference numerals.

[0034] The device 10 according to the invention is advantageously used for testing or checking the dissolution behavior of pharmaceutical products, in particular for simulating the dissolution behavior of the pharmaceutical products in the human body, most preferably for simulating the dissolution behavior of the pharmaceutical products in the human digestive tract. The device 10 is therefore also referred to, among other things, as a dissolution test device 10, dissolution test device 10, or the like.

[0035] The device 10 according to the invention comprises, as shown in Fig. 1, at least one stationary or fixed unit 12 or component or part and at least one rotatable unit 14 or component or part. The rotatable unit or component or part is also referred to below as the rotating or rotating unit or component or part.

[0036] The stationary unit 12 is formed, for example, by a preferably stable support structure or similar frame, such as the housing (not shown) of the device 10.

[0037] The rotatable unit 14 is arranged on or in the at least one stationary unit 12, and is therefore received thereby, and is designed to be rotatable relative to the stationary unit 12, i.e. it rotates on or in the stationary unit 12. The at least one stationary unit 12 and the at least one rotatable unit 14 each comprise a communication module 16, 18, which is referred to below as the stationary communication module 16 and the rotating communication module 18 and via which the at least one stationary unit 12 and the at least one rotatable unit 14 are coupled to one another for contactless communication.

[0038] The terms "couple," "coupled," "connect," or "connected," etc., are understood to mean any manner, known in the art or later developed, in which energy can be transferred between two or more elements, contemplating, but not requiring, the interposition of one or more additional elements. The terms "directly couple," "directly coupled," "directly connect," or "directly connected," etc., imply that the connected elements are either adjacent to one another or connected via a conductor for the transferred energy.

[0039] The stationary communication module 16 of the at least one stationary unit 12 and the rotating communication module 18 of the at least one rotatable unit 14 are arranged in close proximity to one another in a suitable manner. Alternatively, however, the stationary communication module 16 and the rotating communication module 18 could also be arranged in close proximity and then connected to one another for contactless communication.

[0040] In the exemplary embodiment of the device 10 according to the invention, the at least one stationary unit 12 and the at least one rotatable unit 14 are connected to one another via radio for contactless communication. Very preferably, the at least one stationary unit 12 and the at least one rotatable unit 14 are coupled to one another via Bluetooth Low Energy (BLE). Without being shown in detail, it is readily possible to provide a different standard for contactless communication instead, in particular the wireless M-Bus, LPWan, LiFi, WiFi, LoRa, ZigBee, or Z-Wave standards.

[0041] In the embodiment of the device 10 according to the invention, a contactless electrical transmission system, preferably based on Bluetooth, is used for the transmission path of data between the at least one stationary unit 12 and the at least one rotatable unit 14. Specifically, the stationary unit 12 is a control system of the device 10, and the rotatable unit 14 is one or more sensors (for example a temperature sensor and / or density sensor and / or pH sensor and / or sensor for detecting or determining the electrical conductivity, from which the concentration can also be derived, and / or oxygen saturation sensor (residual oxygen sensor) in a rotating stirrer shaft of a dissolution test device, as will be explained in detail below). The sensor(s) is / are for detecting orDetermination of parameters characterizing the dissolution behavior of the pharmaceutical products or parameters of the solution or the medium in which the rotating stirrer shaft is arranged or immersed.

[0042] Alternatively and / or cumulatively, one or more sensors may be provided to detect or determine further parameters, in particular the rotational speed(s) and / or the battery status of the agitator shaft.

[0043] Without being shown in detail in Figs. 1 to 6, the stationary communication module 16 is, as indicated in Fig. 7, arranged or integrated as part of the device 10 according to the invention, preferably on or in the support structure or similar frame or the housing of the device 10.

[0044] In addition, the device 10 carries a corresponding vessel or dissolution test vessel (not shown) in which a solution of the pharmaceutical products is received, which is to be subjected to an examination, a test and a check of its dissolution behavior.

[0045] As further shown in Fig. 1, the device 10 has a stationary drive unit 20 for rotating the rotatable unit 12. The drive unit 20 comprises a motor (not shown) of the device 10, a toothed belt drive 22, a toothed belt 24, a drive driver 25 for rotation transmission and an agitator shaft driver 26 or a height adjustment. The toothed belt drive 22 is rigidly connected to the agitator shaft driver 26. An agitator shaft 28 is assigned to the underside of the agitator shaft driver 26. The agitator shaft 28 is designed as a hollow shaft. The height of the agitator shaft 28 can also be adjusted using the agitator shaft driver 26. In addition, a holder 30 or a holder or similar holding element is assigned to the top of the agitator shaft driver 26.

[0046] Thus, the stirring parts are mechanically connected to a motor via toothed belts. Without being shown in detail, the invention is not limited to this. In alternative embodiments, the stirring parts can be mechanically connected to be rotated by the motor via other suitable means, such as gears, non-toothed belts, or electromagnets.

[0047] As already explained and shown in Fig. 1, the rotatable unit 14 comprises the agitator shaft 24, the agitator shaft driver 22 and the rotating communication module 18.

[0048] 1 and 3 to 6, the rotating communication module 18 and a mobile power supply 32 are accommodated in the holder 30. The mobile power supply 32 is a rechargeable battery. The rotating communication module 18 can also contain a charging module for contactless charging of the mobile power supply 32 (not shown) in order to recharge the battery during use. Without being shown in detail, alternative power sources can be used instead of or in addition to a mobile power supply 32 to supply the rotating communication module 18 with power. In a suitable manner, the rotating communication module 18 can, for example, according to the invention, contain an energy generation device that generates power, for example, from the rotation of the rotating communication module 18, from radiation directed at the energy generation device, or from ambient radiation.

[0049] As clearly shown in Figs. 2 and 3, the rotating communication module 18 is protected from contamination and contact by a housing 34. The housing 34 has openings 36, 38 for a charging socket 40 and a multifunction button 42. The multifunction button 41 is recessed into the housing 34 to prevent accidental contact. The housing 34 and the holder 30 additionally ensure that the rotating communication module 18 and the mobile power supply 32 can be securely installed on the agitator shaft 24.

[0050] As can be further seen from Figs. 4 to 6, the rotating communication module 18 further comprises a circuit board with a transmitter 44, in particular a Bluetooth Low Energy (BLE) transmitter, or rotating contactless communicator, a processor 46, preferably a microcontroller (MCU), a battery connection 48, a wired charging unit or a charging connection 50 for the battery 32 and a signal converter 52 for one or more connected sensors 54.

[0051] The signal converter 52 enables the rotating communication module 18 to transmit the measured data of parameters characterizing the dissolution behavior of the pharmaceutical products or parameters of the solution or medium, for example, the temperature, the density, the pH value, the electrical conductivity (from which the concentration can also be derived), the oxygen saturation (residual oxygen), and / or other parameters, in particular the rotational speed and / or the battery status of the agitator shaft, etc., to the stationary communication module 16. The transmission can, in particular, be time-controlled, threshold-controlled, and / or encrypted.

[0052] The rotating communication module 18 is attached to one end of the agitator shaft 28 by the bracket 30, and at least one sensor 54 is attached to the other end of the agitator shaft 28. The at least one sensor 54 is connected to the rotating communication module 18 via a sensor connection 56 via an electrical connection or conductive wires or similar wire connectors (not shown). This connection can be implemented in the agitator shaft 24.

[0053] The stationary communication module 16 is responsible for storing the received data; the data is stored in a memory to ensure that it is available even in the event of a power interruption. The term "memory" as used here refers to any type of memory that essentially retains its stored content after being disconnected from the power supply, i.e., the stored content can be retrieved after the non-volatile memory is reconnected to the power supply. Examples of non-volatile memory include all types of read-only memory (ROM), non-volatile memory express (NVMe), or magnetic memory.

[0054] Fig. 7 schematically shows the essential elements of the embodiment of the device 10 according to the invention, in which the at least one stationary unit 12 and the at least one rotatable unit 14 are coupled to one another for contactless communication, and are summarized schematically for clarity. The stationary unit 12 is equipped with a Bluetooth Low Energy (BLE) transmitter 44', which interacts with the Bluetooth Low Energy (BLE) transmitter 44 of the rotatable unit 14. The Bluetooth Low Energy (BLE) transmitter 44' is in turn connected to a processor 46', preferably a microcontroller (MCU).

[0055] As already explained above, the rotatable unit 14 is equipped with the Bluetooth Low Energy (BLE) transmitter 44, which interacts with the Bluetooth Low Energy (BLE) transmitter 44' of the stationary unit 12. The Bluetooth Low Energy (BLE) transmitter 44 is connected to the processor 46, preferably a microcontroller (MCU). The processor 46, in turn, communicates with the sensor(s) 54 at the end of the agitator shaft 28.

[0056] Finally, Fig. 8 shows an embodiment of a system 58 according to the invention, which is suitable and intended for testing or checking the dissolution behavior of pharmaceutical products, comprising a plurality of rotatable units 14 for wirelessly coupled communication with one or more stationary units 12. The system 58 comprises a drive base 60 on which a plurality of rotatable units 14 can be arranged. The system 60 also comprises an upper cover 62 with a plurality of openings corresponding to the number of rotatable units 14. Each rotatable unit 14 comprises a stirring shaft 28, a rotating communication module 18 at an upper end, and at least one sensor 54 at a lower end. The system 58 comprises at least one motor (not shown) for rotating the rotatable units 14.

[0057] The individual rotating communication modules 18 are connected to the stationary communication module 16 via a configuration mode with a user interface. For this purpose, each rotating communication module 18 provides a unique identifier. This unique identifier allows the rotating communication module 18 to evaluate the received data. Adjustment data for the individual sensors 54 are stored in the memory of the rotating communication module 18. This memory is non-volatile, meaning that the data remains available even after a power interruption.

[0058] The invention is not limited to the described and illustrated embodiment of the device 10. Without being illustrated in detail, it is possible to combine the various embodiments of the device 10 according to the invention and its individual components with one another or with one another individually and arbitrarily. Thus, instead of a coupled Bluetooth communication, it is readily conceivable to provide other embodiments of coupled communications according to the invention, such as a wireless M-Bus, LPWan, LiFi, WiFi, LoRa, ZigBee, or Z-Wave (radio) standard. Furthermore, the invention provides that the device according to the invention in general and the stationary unit 12 in particular is / are equipped with further additional components, such as a display and an input device or a keyboard.

Claims

Patent claims 1. Device for testing or checking the dissolution behavior of pharmaceutical products with at least one stationary unit (12) and at least one unit (14) arranged on or in the at least one stationary unit (12) and rotatable relative to the stationary unit (12), which are coupled to one another via a communication connection, characterized in that the at least one stationary unit (12) and the at least one rotatable unit (14) are connected to one another by radio for contactless communication.

2. Device according to claim 1, characterized in that the at least one stationary unit (12) and the at least one rotatable unit (14) are connected to one another by means of Bluetooth Low Energy (BLE) or another standard, in particular Wireless M-Bus, LPWan, LiFi, WiFi, LoRa, ZigBee or Z-Wave standard, for contactless communication.

3. Device according to claim 1 or 2, characterized in that the at least one stationary unit (12) and the at least one rotatable unit (14) each comprise a communication module (16, 18) via which the at least one stationary unit (12) and the at least one rotatable unit (14) are connected to one another for contactless communication.

4. Device according to one of claims 1 to 3, characterized in that the communication module (16, 18) of the at least one stationary unit (12) and the at least one rotatable unit (14) each comprises a Bluetooth Low Energy (BLE) transmitter (44, 44') or another Transmitter, in particular a Wireless M-Bus, LPWan, LiFi, WiFi, LoRa, ZigBee or Z-Wave standard Transmitter, includes.

5. Device according to one of claims 1 to 4, characterized in that the communication module (16, 18) of the at least one stationary unit (12) and the at least one rotatable unit (14) each comprises a processor (46, 46'), in particular a microcontroller (MCU), for (further) processing the information.

6. Device according to one of claims 1 to 5, characterized in that the communication module (16, 18) of the at least one stationary unit (12) and the at least one rotatable unit (14) each comprises a memory, in particular a non-volatile memory, preferably a read-only memory (ROM) memory, a non-volatile memory express (NVMe) memory or a magnetic memory, for storing the information.

7. Device according to one of claims 1 to 6, characterized in that the communication module (16, 18) of the at least one stationary unit (12) and the at least one rotatable unit (14) are arranged in close proximity to one another or are arranged in indirect proximity and are connected to one another for contactless communication.

8. Device according to one of claims 1 to 7, characterized in that the at least one rotatable unit (14) comprises a rotatable hollow shaft (28), in particular with a stirrer, and at least one sensor (54) arranged on the hollow shaft (28) for detecting parameters characterizing the dissolution behavior of the pharmaceutical products and / or parameters of the solution or medium, in particular temperatures, densities, pH values, electrical conductivities, from which additional concentrations can also be derived, oxygen saturation(s) (residual oxygen), and / or for detecting or determining further parameters tern, in particular speeds and / or the battery status of the stirrer(s).

9. Device according to claim 8, characterized in that the at least one sensor (54) is arranged at one end, in particular the free end, of the hollow shaft (28) and is connected to the communication module (18) of the rotatable unit (14) at the other end of the hollow shaft (28) via an electronic connection through the hollow shaft (28) to the communication module (18) of the rotatable unit (14).

10. A system for forming with a device according to any one of claims 1 to 9, comprising at least one or more additional stationary units (12) and one or more additional rotatable units (14).

11. Method for operating a device according to one of claims 1 to 9 or a system according to claim 10, characterized in that the at least one stationary unit (12) and the at least one rotatable unit (14) are connected to one another by radio for contactless communication, wherein analog information detected by the at least one sensor (54) of the at least one rotatable unit (14) is digitized, coupled to the stationary unit (12) and subsequently processed by the stationary unit (12).

12. A method for operating a device according to claim 11, characterized in that the information transmitted from the at least one rotatable unit (14) coupled to the stationary unit (12) is processed by a processor (46') of the stationary unit (12).

13. A method for operating a device according to claim 11 or 12, characterized in that the at least one stationary unit (12) and the at least one rotatable unit (14) are continuously coupled to one another become.

14. A method for operating a device according to one of claims 10 to 13, characterized in that the at least one stationary unit (12) and the at least one rotatable unit (14) are coupled to one another and to one or more additional rotatable units (14).

15. Use of a device according to one of claims 1 to 9 or a system according to claim 10 for testing or checking the dissolution behavior of pharmaceutical products, in particular for simulating the dissolution behavior of the pharmaceutical products in the human body, very preferably for simulating the dissolution behavior of the pharmaceutical products in the human digestive tract.

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